ABSTRACT The Light Microscopy Core Facility (LMCF) at Duke serves as the Light Microscopy Shared Resource for the Duke Cancer Institute (DCI). The facility offers affordable and efficient access to more than $6 million of confocal and conventional fluorescence microscopes and image analysis resources to all members of the University and the Medical Center. Dedicated staff provides training and full technical support for all the instruments; DCI members receive priority for training. Trained users can access the equipment 24 hours a day. The LMCF is funded by the DCI (including the CCSG), the Duke University School of Medicine, the Duke University Office of the Provost, the National Institutes of Health, and the North Carolina Biotechnology Center, in addition to user fees. The LMCF provides access to confocals (eight), live cell fluorescence microscopes, spinning disk, multiphoton, TIRF and more to allow fluorescence imaging of samples ranging from fixed immunofluorescence slides and live cell tissue culture models, to model organisms and intravital imaging of mice. Essentially all standard optical sectioning and microscopy methods are present - confocal, resonant scanning confocal, spinning disk, live cell imaging with several modalities, long-term incubated time-lapse, multiphoton including with scale-cleared samples allowing imaging up to 8 mm into the sample, photoactivation/photoconversion and photokinetic (FRAP, FLIP) capabilities, time-correlated single-photon counting fluorescence lifetime imaging and a broad range of analysis capabilities are available, with training and assistance, to all users. The shared resource's three full-time PhD-level staff members provide assistance with all aspects of imaging, including processing and quantitative analysis of images. From 2009 through 2013, LMCF was used by over 1,200 people (over 2,200 trainings) from over 360 labs for over 106,000 hours of imaging over 41,000 sessions. In 2012 LMCF was used 10,611 times by 223 labs for 28,622 hours of imaging and analysis. In 2012, 96 of the 223 labs (43%) were from the DCI; of those, 82 (85%) had peer-reviewed funding and 14 (15%) did not. 226 publications from DCI members resulted from LMCF usage during the funding period. LMCF's DCI users represent all nine CCSG-recognized Research Programs. Booking is done on a first-come, first-served basis with some limits to promote efficient use. The significant number of machines in the facility provides good capacity, availability of the machines is good, and bottlenecks are generally few and temporary. In recognition of the CCSG-contribution, DCI members are prioritized for training and assistance. The facility's ongoing priority is continued support of the users and systems for continued productivity, with acquisition and implementation of new technologies if they prove valuable.